Two-dimensional (2-D) intersymbol-interference (ISI) channels have become practically relevant in various data recording technologies such as two-dimensional magnetic recording (TDMR), optical holographic memories as well as in other areas such as pixelated wireless optical channels and 2-D grid networks. From a signal processing viewpoint, data recording systems in 2-D have advantages over traditional 1-D systems. 2-D recording systems are less sensitive to timing instabilities due to wider tracks and hence not restrictive to the size of sensory read elements. With clever 2-D signal processing, guard bands between tracks can be avoided. This improves format efficiency. Lastly, if 2-D ISI can be handled beneficially to gain signal-to-noise ratio (SNR) by appropriate signal processing.